Peru's several climates and contrasting surface features have produced a rich diversity of flora and fauna. Where the coastal desert is not barren of life, there are sparse xerophytic shrub, cactus, and algarroba, and a few palm oases along the perennially flowing rivers from the Andes. Where the sea mist (garúa) strikes against the rising slopes between 800 and 1,400 m (2,600 and 4,600 ft), a dense belt of lomas, flowering plants, and grasses (important for grazing) grows. Perennial shrubs, candelabra cacti, and intermontane pepper trees account for much of the western slope vegetation in the higher altitudes and forests of eucalyptus have been planted. High-altitude vegetation varies from region to region, depending on the direction and intensity of sunlight. Tola grows in profusion at 3,400 m (11,000 ft) in the southern volcanic regions; bunch puna grasses may be found at 3,700 m (12,000 ft). On the brow (ceja) of the eastern slopes, mountain tall grass and sparse sierra cactus and low shrub give way at 900 m (3,000 ft) to rain forests and subtropical vegetation. As the eastern slopes descend, glaciers are remarkably close to tropical vegetation. The 601,000 sq km (232,000 sq mi) of eastern selva, with 18 rivers and 200 tributaries, contain the dense flora of the Amazon basin. Such native plants as sarsaparilla, barbasco, cinchona, coca, ipecac, vanilla, leche caspi, and curare have become commercially important, as well as the wild rubber tree, mahogany, and other tropical woods.
For centuries, vast colonies of pelicans, gannets, and cormorants have fed on the schools of anchovies that graze the rich sea pastures of the Humboldt Current and have deposited their excrement on the islands to accumulate, undisturbed by weather, in great quantities of guano. This natural fertilizer was used by the pre-Inca peoples, who carried it on their backs to the sierra. Forgotten during the days of colonial gold greed, guano attracted the attention of scientists in 1849, when its rich nitrogen content was analyzed as 14–17%. For 40 years thereafter, Peru paid many of its bills by exporting guano to exhausted croplands of Europe. Guano has since been largely replaced in the international market by synthetic fertilizers.
The rich marine plant life off the Peruvian coast attracts a wealth of marine fauna, the most important of which are anchoveta, tuna, whale, swordfish, and marlin. Characteristic of the Andes are the great condor, ducks, and other wild fowl. The vizcacha, a mountain rodent, and the chinchilla are well known, as is the puma, or mountain lion. Peru is famous for its American members of the camel family—the llama, alpaca, huarizo, and guanaco—all typical grazing animals of the highlands. The humid forests and savannas of eastern Peru contain almost half the country's species of fauna, including parrots, monkeys, sloths, alligators, paiche fish, piranhas, and boa constrictors, all common to the Amazon Basin.